KVM: s390: Add support for channel I/O instructions.
Add a new capability, KVM_CAP_S390_CSS_SUPPORT, which will pass
intercepts for channel I/O instructions to userspace. Only I/O
instructions interacting with I/O interrupts need to be handled
in-kernel:
- TEST PENDING INTERRUPTION (tpi) dequeues and stores pending
interrupts entirely in-kernel.
- TEST SUBCHANNEL (tsch) dequeues pending interrupts in-kernel
and exits via KVM_EXIT_S390_TSCH to userspace for subchannel-
related processing.
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/s390/kvm/trace-s390.h b/arch/s390/kvm/trace-s390.h
index 95fbc1ab..13f30f5 100644
--- a/arch/s390/kvm/trace-s390.h
+++ b/arch/s390/kvm/trace-s390.h
@@ -204,6 +204,26 @@
);
+/*
+ * Trace point for enabling channel I/O instruction support.
+ */
+TRACE_EVENT(kvm_s390_enable_css,
+ TP_PROTO(void *kvm),
+ TP_ARGS(kvm),
+
+ TP_STRUCT__entry(
+ __field(void *, kvm)
+ ),
+
+ TP_fast_assign(
+ __entry->kvm = kvm;
+ ),
+
+ TP_printk("enabling channel I/O support (kvm @ %p)\n",
+ __entry->kvm)
+ );
+
+
#endif /* _TRACE_KVMS390_H */
/* This part must be outside protection */